Question

EventsActivity是我的标签之一（3个标签有3个活动）。

问题是：

此活动可以显示为列表吗？如果是，我应该使用哪个列表（SimpleList，ArrayList等）？
我使用了ArrayList HashMap但意外停止了。我该如何解决这个问题？

我的代码中有一些例子：

班级EventsActivity延伸ListActivity。这是我的一个标签。

班级EventDataSet。 Getter和setter方法。

班级EventXMLHandler。 XML Handler。

类转换器。转换日期和时间。

布局文件夹：

eventitem.xml
listplaceholder.xml

EventsActivity.class

public class EventsActivity extends ListActivity {

    EventDataSet eventDataSet = null;
    ArrayList<HashMap<String, String>> mylist =
        new ArrayList<HashMap<String, String>>();

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.listplaceholder);
        try {
            /** Handling XML */
            /** Send URL to parse XML Tags */
            /*URL sourceUrl */

            /** Create handler to handle XML Tags ( extends DefaultHandler ) */

        } catch (Exception e) {

        }

        /** Get result from EventXMLHandler EventDataSet Object */
        eventDataSet = EventXMLHandler.eventDataSet;

        for (int i = 0; i < eventDataSet.getName().size(); i++) {

            HashMap<String, String> map = new HashMap<String, String>();
            map.put("name", "Name: " + eventDataSet.getName().get(i));
            map.put("createat", "Create-At: " +
                Convertor.getDateTimeDDMMYY(
                    eventDataSet.getCreateat().get(i)));

            mylist.add(map);

        }

        ListAdapter adapter = new SimpleAdapter(this, mylist ,
                R.layout.eventitem,  new String[] { "name", "createat" }, 
                new int[] { R.id.item_title, R.id.item_subtitle });

            setListAdapter(adapter);


        }

listplaceholder.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">    

    <ListView android:id="@id/android:list"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:drawSelectorOnTop="false" />

    <TextView android:id="@id/android:empty"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="No data"/>


</LinearLayout>

eventitem.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="5dp">

    <TextView android:id="@+id/item_title"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:padding="2dp"
        android:textSize="15dp"
        android:layout_weight="1" />

    <TextView android:id="@+id/item_subtitle"
        android:layout_alignParentRight="true"  
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:padding="2dp"
        android:textSize="13dp"
        android:layout_weight="1" />
</LinearLayout>

logcat的

08-18 14:11:00.112: ERROR/AndroidRuntime(294): Uncaught handler: thread main exiting due to uncaught exception
08-18 14:11:00.142: ERROR/AndroidRuntime(294): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ctg/com.ctg.EventsActivity}: java.lang.NullPointerException
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.app.ActivityThread.startActivityNow(ActivityThread.java:2335)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:648)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.widget.TabHost.setCurrentTab(TabHost.java:320)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:129)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:379)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.view.View.performClick(View.java:2364)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.view.View.onTouchEvent(View.java:4179)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.view.View.dispatchTouchEvent(View.java:3709)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:852)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1659)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.app.Activity.dispatchTouchEvent(Activity.java:2061)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1691)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.os.Looper.loop(Looper.java:123)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.app.ActivityThread.main(ActivityThread.java:4363)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at java.lang.reflect.Method.invokeNative(Native Method)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at java.lang.reflect.Method.invoke(Method.java:521)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at dalvik.system.NativeStart.main(Native Method)
08-18 14:11:00.142: ERROR/AndroidRuntime(294): Caused by: java.lang.NullPointerException
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at com.ctg.EventsActivity.onCreate(EventsActivity.java:64)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
08-18 14:11:00.142: ERROR/AndroidRuntime(294):     ... 30 more

Answer 1

是的，它可以。

1.1。这一切都取决于您的代码以及您如何获取信息。如果从数据库中获取信息，最容易使用的适配器将在我的操作中使用CursorAdapter，如果从解析中得到它，我将使用ArrayAdapter。我会创建自己的自定义适配器，扩展ArrayAdapter。 Here is an example.还有很多其他的例子。

2：你的崩溃。查看EventsActivity中的第64行并在此处发布。否则，请包含完整的源代码以及所有导入和包，以便我们查看。

TabHost的活动可以成为ListAcitivty吗？

1 个答案: